Total diastereoselectivity in the one-pot multistep reaction of (R-s)-(+)-{[(4-methylphenyl)sulfinyl]methyl}-1-oxa-4-azaspiro[4.5]dec-3-ene and E-methyl cinnamate. An approach to (2S,4S,5R,6R)-2-(hydroxymethyl)-4,6-diphenyl)-1-azabicycle[3.3.1]nonane

摘要

The base-mediated reaction of enantiomerically pure alpha-sulfinylketimine (+)-1 with (E)-methyl cinnamate afforded (+)-5a in a one-pot procedure with complete diastereoselectivity. A sole diastereomer of the eight possible ones was isolated which revealed the stereocantrol of the chiral sulfinyl group in the construction of the three new stereogenic centres. The absolute configuration of stereocentres introduced in (+)-5a was assigned on the basis of H-1 NMR data and a single X-ray structure. (C) 2008 Elsevier Ltd. All rights reserved.